MINOR: listener: move the network namespace to the struct settings

The netns is common to all listeners/receivers and is used to bind the
listening socket so it must be in the receiver settings and not in the
listener. This removes some yet another set of unnecessary loops.
diff --git a/src/sock.c b/src/sock.c
index 5899d44..a9dd5f2 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -388,8 +388,8 @@
 	if (l->bind_conf->settings.interface)
 		if_namelen = strlen(l->bind_conf->settings.interface);
 #ifdef USE_NS
-	if (l->netns)
-		ns_namelen = l->netns->name_len;
+	if (l->bind_conf->settings.netns)
+		ns_namelen = l->bind_conf->settings.netns->name_len;
 #endif
 
 	while (xfer_sock) {
@@ -398,7 +398,7 @@
 		    (ns_namelen == xfer_sock->ns_namelen) &&
 		    (!if_namelen || strcmp(l->bind_conf->settings.interface, xfer_sock->iface) == 0) &&
 #ifdef USE_NS
-		    (!ns_namelen || strcmp(l->netns->node.key, xfer_sock->namespace) == 0) &&
+		    (!ns_namelen || strcmp(l->bind_conf->settings.netns->node.key, xfer_sock->namespace) == 0) &&
 #endif
 		    l->proto->addrcmp(&xfer_sock->addr, &l->addr) == 0)
 			break;